Stjerneborg

When Uraniborg turned out to be too small and two unstable for satisfactory astronomical observations, Tycho Brahe built another observatory, Stjerneborg. It didn't look quite as fancy in part because it was mostly underground, but it cost the Danish State plenty. It was built right next door to Uraniborg, and they were intended to eventually be connected by an underground tunnel. The major improvement of Stjerneborg over Uraniborg is that it was built on a foundation of solid granite pillars, with the instruments housed underground, protected from the wind and weather. The observatory was capped with a large rotating dome, with hatches that could be opened to let the instruments view the heavens.

Built in 1586 on the island of Hven (AKA Ven) in Sweden, Stjerneborg was five circular pits (big pits) dig into the ground around a large square pit. The five pits each housed some large astronomical instrument - the largest, the one with the aforementioned rotating dome, had a large Equatorial instrument. The other four contained a height and azimuthquadrant, an armillar-sphere, a sextant for distance measurements, and a height and azimuth quadrant surrounded by a steelsquare. They all had roofs that could be opened up. Other than this it was a little sparse, but he had Uraniborg right next door.